Abstract: AIM: To investigate the pharmacokinetics and tissue distribution of daurisoline (DS)after administration in rabbits. METHODS: Single dose of 2.5, 5 or 10 mg·kg^-1 DS of body weight was administrated in rabbits. The tissue distribution of DS (10 mg·kg^-1)was investigated, and the concentrations in plasma and tissues were measured by a validated high performance liquid chromatography method. RESULTS: Plasma concentration-time profiles were adequately described by a twocompartment open model. The main pharmacokinetic parameters after iv DS 2.5, 5 and 10 mg·kg^-1 were as follows: T_1/2β were 3.0 ±0.6, 3.4 ±0.9 and 6.9 ±0.6 h, respectively, Cls were 3.1 ±0.6, 3.6 ±0.4 and 4.4 ± 0.3 L·h·kg^-1, respectively, V_d were 13.1 ±2.7, 18.0 ±6.2 and 43.6 ±4.4 L·kg^-1, respectively, and AUC_0~t were 0.84 ±0.13, 1.41 ±0.17 and 2.30 ±0.18 mg·h·L^-1, respectively. At dosages of 2.5 and 5 mg·kg^-1, no statistically significant difference existed in main pharmacokinetic parameters. However, T_1/2β and C₀ increased nonproportionally when the dosage was 10 mg·kg^-1. CONCLUSION: Across the dosages of 2.5-5 mg·kg^-1, DS demonstrates linear kinetics. However, a nonlinear kinetics is found at dosage of 10 mg·kg^-1. Assessment of tissue concentrations of DS reveals preferential distribution to the lung, kidney, spleen, and liver, and displays substantial penetration into tissues.

Key words: daurisoline, high performance liquid chromatography, pharmacokinetics, tissue distribution